MPEG is a series of software standards for digital video compression with good efficiency for a package type medium, such as for entertainment and educational software. In "interactive video playback," the user expects that the video playback is instantaneous from a compressed bitstream recorded, for example, on a CD-ROM. However, time is required for the read head to search for the target track, and unlike other media that record video in raw data format, such as a laser disk (using PCM recording by FM), video playback from a CD-ROM introduces certain unavoidable delays. This has become a key problem in using MPEG technology for real time entertainment and educational software.
The two predominant MPEG standards are referred to as MPEG-1 and MPEG-2. The MPEG-1 standard generally concerns inter-field data reduction using block-based motion compensation prediction (MCP), which generally uses temporal differential pulse code modulation (DPCM). The MPEG-2 standard is similar to the MPEG-1 standard, but includes extensions to cover a wider range of applications, including interlaced digital video such as high definition television (HDTV).